Update PR based on feedback: add BuildGEP and ConstGEP variants that take an explicit set of GEPNoWrapFlags. Also, actually clone the no-wrap flags for constant GEP expressions, and add a test to verify this

Author: Benjins

llvm/docs/ReleaseNotes.rst

@@ -293,9 +293,11 @@ They are described in detail in the `debug info migration guide <https://llvm.or
   * ``LLVMGetTargetExtTypeNumTypeParams``/``LLVMGetTargetExtTypeTypeParam``
   * ``LLVMGetTargetExtTypeNumIntParams``/``LLVMGetTargetExtTypeIntParam``
 
-* Added the following functions for accessing/changing the no-wrap flags for a
+* Added the following functions for accessing/setting the no-wrap flags for a
   GetElementPtr instruction
 
+  * ``LLVMBuildGEPWithWrapFlags``
+  * ``LLVMConstGEPWithWrapFlags``
   * ``LLVMGEPGetNoWrapFlags``
   * ``LLVMGEPSetNoWrapFlags``
 

llvm/include/llvm-c/Core.h

@@ -2409,6 +2409,10 @@ LLVMValueRef LLVMConstGEP2(LLVMTypeRef Ty, LLVMValueRef ConstantVal,
 LLVMValueRef LLVMConstInBoundsGEP2(LLVMTypeRef Ty, LLVMValueRef ConstantVal,
                                    LLVMValueRef *ConstantIndices,
                                    unsigned NumIndices);
+LLVMValueRef LLVMConstGEPWithWrapFlags(LLVMTypeRef Ty, LLVMValueRef ConstantVal,
+                                       LLVMValueRef *ConstantIndices,
+                                       unsigned NumIndices,
+                                       LLVMGEPNoWrapFlags WrapFlags);
 LLVMValueRef LLVMConstTrunc(LLVMValueRef ConstantVal, LLVMTypeRef ToType);
 LLVMValueRef LLVMConstPtrToInt(LLVMValueRef ConstantVal, LLVMTypeRef ToType);
 LLVMValueRef LLVMConstIntToPtr(LLVMValueRef ConstantVal, LLVMTypeRef ToType);
@@ -4391,6 +4395,11 @@ LLVMValueRef LLVMBuildGEP2(LLVMBuilderRef B, LLVMTypeRef Ty,
 LLVMValueRef LLVMBuildInBoundsGEP2(LLVMBuilderRef B, LLVMTypeRef Ty,
                                    LLVMValueRef Pointer, LLVMValueRef *Indices,
                                    unsigned NumIndices, const char *Name);
+LLVMValueRef LLVMBuildGEPWithWrapFlags(LLVMBuilderRef B, LLVMTypeRef Ty,
+                                       LLVMValueRef Pointer,
+                                       LLVMValueRef *Indices,
+                                       unsigned NumIndices, const char *Name,
+                                       LLVMGEPNoWrapFlags WrapFlags);
 LLVMValueRef LLVMBuildStructGEP2(LLVMBuilderRef B, LLVMTypeRef Ty,
                                  LLVMValueRef Pointer, unsigned Idx,
                                  const char *Name);

llvm/lib/IR/Core.cpp

@@ -1685,6 +1685,32 @@ static int map_from_llvmopcode(LLVMOpcode code)
     llvm_unreachable("Unhandled Opcode.");
 }
 
+/*-- GEP wrap flag conversions*/
+
+static GEPNoWrapFlags mapFromLLVMGEPNoWrapFlags(LLVMGEPNoWrapFlags GEPFlags) {
+  GEPNoWrapFlags NewGEPFlags;
+  if ((GEPFlags & LLVMGEPFlagInBounds) != 0)
+    NewGEPFlags |= GEPNoWrapFlags::inBounds();
+  if ((GEPFlags & LLVMGEPFlagNUSW) != 0)
+    NewGEPFlags |= GEPNoWrapFlags::noUnsignedSignedWrap();
+  if ((GEPFlags & LLVMGEPFlagNUW) != 0)
+    NewGEPFlags |= GEPNoWrapFlags::noUnsignedWrap();
+
+  return NewGEPFlags;
+}
+
+static LLVMGEPNoWrapFlags mapToLLVMGEPNoWrapFlags(GEPNoWrapFlags GEPFlags) {
+  LLVMGEPNoWrapFlags NewGEPFlags = 0;
+  if (GEPFlags.isInBounds())
+    NewGEPFlags |= LLVMGEPFlagInBounds;
+  if (GEPFlags.hasNoUnsignedSignedWrap())
+    NewGEPFlags |= LLVMGEPFlagNUSW;
+  if (GEPFlags.hasNoUnsignedWrap())
+    NewGEPFlags |= LLVMGEPFlagNUW;
+
+  return NewGEPFlags;
+}
+
 /*--.. Constant expressions ................................................--*/
 
 LLVMOpcode LLVMGetConstOpcode(LLVMValueRef ConstantVal) {
@@ -1789,6 +1815,17 @@ LLVMValueRef LLVMConstInBoundsGEP2(LLVMTypeRef Ty, LLVMValueRef ConstantVal,
   return wrap(ConstantExpr::getInBoundsGetElementPtr(unwrap(Ty), Val, IdxList));
 }
 
+LLVMValueRef LLVMConstGEPWithWrapFlags(LLVMTypeRef Ty, LLVMValueRef ConstantVal,
+                                       LLVMValueRef *ConstantIndices,
+                                       unsigned NumIndices,
+                                       LLVMGEPNoWrapFlags WrapFlags) {
+  ArrayRef<Constant *> IdxList(unwrap<Constant>(ConstantIndices, NumIndices),
+                               NumIndices);
+  Constant *Val = unwrap<Constant>(ConstantVal);
+  return wrap(ConstantExpr::getGetElementPtr(
+      unwrap(Ty), Val, IdxList, mapFromLLVMGEPNoWrapFlags(WrapFlags)));
+}
+
 LLVMValueRef LLVMConstTrunc(LLVMValueRef ConstantVal, LLVMTypeRef ToType) {
   return wrap(ConstantExpr::getTrunc(unwrap<Constant>(ConstantVal),
                                      unwrap(ToType)));
@@ -3090,30 +3127,6 @@ LLVMTypeRef LLVMGetAllocatedType(LLVMValueRef Alloca) {
 
 /*--.. Operations on gep instructions (only) ...............................--*/
 
-static GEPNoWrapFlags mapFromLLVMGEPNoWrapFlags(LLVMGEPNoWrapFlags GEPFlags) {
-  GEPNoWrapFlags NewGEPFlags;
-  if ((GEPFlags & LLVMGEPFlagInBounds) != 0)
-    NewGEPFlags |= GEPNoWrapFlags::inBounds();
-  if ((GEPFlags & LLVMGEPFlagNUSW) != 0)
-    NewGEPFlags |= GEPNoWrapFlags::noUnsignedSignedWrap();
-  if ((GEPFlags & LLVMGEPFlagNUW) != 0)
-    NewGEPFlags |= GEPNoWrapFlags::noUnsignedWrap();
-
-  return NewGEPFlags;
-}
-
-static LLVMGEPNoWrapFlags mapToLLVMGEPNoWrapFlags(GEPNoWrapFlags GEPFlags) {
-  LLVMGEPNoWrapFlags NewGEPFlags = 0;
-  if (GEPFlags.isInBounds())
-    NewGEPFlags |= LLVMGEPFlagInBounds;
-  if (GEPFlags.hasNoUnsignedSignedWrap())
-    NewGEPFlags |= LLVMGEPFlagNUSW;
-  if (GEPFlags.hasNoUnsignedWrap())
-    NewGEPFlags |= LLVMGEPFlagNUW;
-
-  return NewGEPFlags;
-}
-
 LLVMBool LLVMIsInBounds(LLVMValueRef GEP) {
   return unwrap<GEPOperator>(GEP)->isInBounds();
 }
@@ -3936,6 +3949,16 @@ LLVMValueRef LLVMBuildInBoundsGEP2(LLVMBuilderRef B, LLVMTypeRef Ty,
       unwrap(B)->CreateInBoundsGEP(unwrap(Ty), unwrap(Pointer), IdxList, Name));
 }
 
+LLVMValueRef LLVMBuildGEPWithWrapFlags(LLVMBuilderRef B, LLVMTypeRef Ty,
+                                       LLVMValueRef Pointer,
+                                       LLVMValueRef *Indices,
+                                       unsigned NumIndices, const char *Name,
+                                       LLVMGEPNoWrapFlags WrapFlags) {
+  ArrayRef<Value *> IdxList(unwrap(Indices), NumIndices);
+  return wrap(unwrap(B)->CreateGEP(unwrap(Ty), unwrap(Pointer), IdxList, Name,
+                                   mapFromLLVMGEPNoWrapFlags(WrapFlags)));
+}
+
 LLVMValueRef LLVMBuildStructGEP2(LLVMBuilderRef B, LLVMTypeRef Ty,
                                  LLVMValueRef Pointer, unsigned Idx,
                                  const char *Name) {

llvm/test/Bindings/llvm-c/echo.ll

@@ -25,6 +25,9 @@ module asm "classical GAS"
 
 @const_gep = global ptr getelementptr (i32, ptr @var, i64 2)
 @const_inbounds_gep = global ptr getelementptr inbounds (i32, ptr @var, i64 1)
+@const_gep_nuw = global ptr getelementptr nuw (i32, ptr @var, i64 1)
+@const_gep_nusw = global ptr getelementptr nusw (i32, ptr @var, i64 1)
+@const_gep_nuw_inbounds = global ptr getelementptr nuw inbounds (i32, ptr @var, i64 1)
 
 @aliased1 = alias i32, ptr @var
 @aliased2 = internal alias i32, ptr @var

llvm/tools/llvm-c-test/echo.cpp

@@ -412,10 +412,9 @@ static LLVMValueRef clone_constant_impl(LLVMValueRef Cst, LLVMModuleRef M) {
       SmallVector<LLVMValueRef, 8> Idx;
       for (int i = 1; i <= NumIdx; i++)
         Idx.push_back(clone_constant(LLVMGetOperand(Cst, i), M));
-      if (LLVMIsInBounds(Cst))
-        return LLVMConstInBoundsGEP2(ElemTy, Ptr, Idx.data(), NumIdx);
-      else
-        return LLVMConstGEP2(ElemTy, Ptr, Idx.data(), NumIdx);
+
+      return LLVMConstGEPWithWrapFlags(ElemTy, Ptr, Idx.data(), NumIdx,
+                                       LLVMGEPGetNoWrapFlags(Cst));
     }
     default:
       fprintf(stderr, "%d is not a supported opcode for constant expressions\n",
@@ -768,8 +767,9 @@ struct FunCloner {
         for (int i = 1; i <= NumIdx; i++)
           Idx.push_back(CloneValue(LLVMGetOperand(Src, i)));
 
-        Dst = LLVMBuildGEP2(Builder, ElemTy, Ptr, Idx.data(), NumIdx, Name);
-        LLVMGEPSetNoWrapFlags(Dst, LLVMGEPGetNoWrapFlags(Src));
+        Dst =
+            LLVMBuildGEPWithWrapFlags(Builder, ElemTy, Ptr, Idx.data(), NumIdx,
+                                      Name, LLVMGEPGetNoWrapFlags(Src));
         break;
       }
       case LLVMAtomicRMW: {